The Black Widow Spider is a deadly spider that inhabits
Northern America. It can grow up to one inch in length and
is a shiny black spider with an hourglass-shaped red mark on
the underside of its abdomen.

The members of the "Widow" spider family like to live in
dry, warm places that have mild winters. For this reason
they are most often found in the southwestern and eastern
part of the United States. They spin irregular webs in
crevices and dark places that are protected from the
elements.

More often than not a dog is bitten by a Black Widow spider
when it goes poking its nose in where it isn't wanted. Both
the female and the male Black Widow spider are venomous but
only the female gets large enough that the venom will injure
a dog.

The Black Widow's venom is classified as a nerve toxin and
one bite from a Black Widow can severely affect or kill a
small dog. And the neurotoxin venom will in generally affect
young animals much more severely than full grown adults.

The Black Widow is not an aggressive spider, thankfully, and
will only bite when it feels it has to defend itself. But
the effects of the venom can be seen right away after the
bite. See more info about Black Widow Spiders on ourstuffed spider page.

Here is what you need to watch for:

- Extreme pain in the area of the bite
- Muscle tremors
- Rigid muscles
- Paralysis
- Death

Death usually occurs because the neurotoxin arrests the
muscles and nerves that control breathing. If you suspect
your dog or child has been bitten by a Black Widow spider
you need to call for help immediately. The longer a person
or pet goes without medical help the more likely it is that
the injury will be very serious or even fatal.

Currently there is no way to immediately detect whether or
not a dog has been bitten by a Black Widow spider unless you
find the offending spider. Otherwise the condition is
usually determined by whether or not the dog has been in
vicinity frequented by Black Widow spiders, and a physical
exam reveals a spider bite, muscle rigidity, spasms and
difficulty breathing.

There is antivenom available that has reversed the effect of
the venom in people but it hasn't been further developed for
canines because of the cost. The antivenom is available in
human hospitals, but there are other treatments that your
veterinarian can try, such as:

With veterinary treatment most dogs will survive the bite of
a Black Widow.

There is nothing that can be done for your dog at home. Do
not apply a tourniquet above the spider bite. This reduces
blood flow to that part of the body and does nothing to stop
or counteract the poison. Try to keep your dog calm and
quiet and take the dog to the veterinarian as soon as
possible.

The best way to prevent your dog from being bitten by a
Black Widow spider is to not allow your dog in locations or
around places where Black Widow spiders dwell. Look around
your property for Black Widow spiders and if you see any
contact an exterminator to rid your property of them.

Black Widow spiders are famous for being in wood piles and
in old sheds, outbuildings and dry wells. Be careful around
any area that has been deserted for a long time and is dark
and dry. Black Widow spider bites are dangerous to humans
too.

Black Widow spiders are a serious threat to the safety of
your pet and your family. You shouldn't allow them to settle
on your property if there is any way to prevent it. Be sure
to have your property inspected for dangerous pests and
remove them when needed. And do not allow your children,
dogs or other pets to explore places that may have Black
Widow spiders, like old abandoned sheds or old wood piles.

Brown Recluse Spider Bites in Dogs

The Brown Recluse Spider, (Loxosceles reclusa) is native to
the southern and Midwestern United States but has spread to
other places via its habit hiding in human property. The
Brown Recluse spider got its common name because of its
habits in living hidden under objects in undisturbed areas.

The spider defends itself by biting but it isn't aggressive
towards creatures that it doesn't consider prey.
Unfortunately, when a Brown Recluse Spider feels threatened
and bites, its bite is very venomous.

Most Brown Recluse spider bites in dogs occur when a dog
steps or lies on the spider. The effect of the venom on the
dog that was bitten depends on the amount of venom that was
injected and how sensitive the dog is to the venom. The
effects of the venom can be no effect at all, delayed or
immediate.

If your dog is bitten by a spider, try to capture the spider
so that it can be identified and be sure to get a
veterinarian's advice as soon as possible. If you think that
the spider was a brown recluse and you can't get to your
veterinarian right away then call poison control. Apply an
antiseptic solution to the bite to prevent further infection
and apply an ice pack to the area to relieve swelling and
pain from the bite wound.

If there is a severe reaction the bite mark may sting and
that will be followed by overwhelming pain. In a not so
serious case the effects of the bite may be felt in two to
eight hours after being bitten. The bite mark will look like
a blister with badly swollen tissue all around it.

After twenty four to thirty-six hours there may be a
systemic reaction where the dog may suffer from
restlessness, chills, fever, weakness, joint pain and
nausea. The area where the spider bit the dog will be
swollen and the skin around it will be hard.

The Brown Recluse spider's venom is not a neurotoxin like
some spider venoms. Instead it is venom that contains an
enzyme that breaks down cellular membranes and the tissue
that was affected by the venom will slough off, exposing the
underlying tissue.

After another twenty-four hours the bite wound area can
become what is called a "volcano lesion," that is, a hole in
the skin caused by damage and gangrenous tissue. The wound
can range in size from the size of a thumbnail to the span
of an entire hand.

The ulcerating sore in the sunken tissue area slowly heals
for around six to eight weeks. Full recovery from the bite
and resulting wound can take up to several months and the
scarring can be permanent. In humans plastic surgery is
often needed, sometimes along with skin grafts to correct
the area.

There is no real effective antivenom for the Brown Recluse
spider's venom. The veterinarian may administer a high dose
of cortisone-type hormone in order to stop hemolysis or any
other secondary complications. A drug called Dapsone that is
used to treat leprosy has had some limited success in
counteracting the venom and reducing the degree of the
tissue damage from the spider venom.